Grease-collecting heat exchanger installation

ABSTRACT

A heat exchanger with a set of channels through which grease laden air travels. Relatively cool air passes through the heat exchanger in a second set of channels. Washing means including liquid tubes within the first set of channels is provided for washing collected grease from the surfaces defining the first set of channels. A cooking facility including a hood for collecting grease laden air connected to a heat exchanger. Relatively cool air from an outside source passes through the heat exchanger to promote the collection of grease in the exchanges from the grease laden air received from the hood. The air from the outside source is raised in temperature on passing through the exchanger. Such heated air may be used as a source of heat for heating a building enclosure.

United States Patent [191 Darm [111 3,827,343 [451 Aug. 6, 1974GREASE-COLLECTING HEAT EXCHANGER INSTALLATION [76] Inventor: William J.Darm, 5815 S.W.

Tucker, Beaverton, Oreg. 97005 [22] Filed: May 12, 1972 [21] Appl. No.:252,909

Primary Examiner-Charles Sukalo Attorney, Agent, or Firm-Klarquist,Sparkman, Campbell, Leigh, Hall & Whinston 5 7] ABSTRACT A heatexchanger with a set of channels through which grease laden air travels.Relatively cool air passes through the heat exchanger in a second set ofchannels. Washing means including liquid tubes within the first set ofchannels is provided for washing collected grease from the surfacesdefining the first set of channels. A cooking facility including a hoodfor collecting grease laden air connected to a heat exchanger.Relatively cool air from an outside source passes through the heatexchanger to promote the collection of grease in the exchanges from thegrease laden air received from the hood. The air from the outside sourceis raised in temperature on passing through the exchanger. Such heatedair may be used as a source of heat for heating a building enclosure.

5 Claims, 2 Drawing Figures PAIENIEWB 61 14 I 3,827,343

SHEEY 1 BF 2 l l l ,i

I I l GREASE-COLLECTING IIEAT EXCHANGER INSTALLATION BACKGROUND OF THEINVENTION This invention relates generally to apparatus for removinggrease from grease laden air, utilizing a heat exchanger for thecollection by solidification of the grease.

In an embodiment of the invention, a cooking facility is contemplated,provided with a hood for collecting grease and contaminant laden airgiven off during the cooking process. Such is channeled through a set ofexchanger channels in a heat exchanger, where grease in the air becomesdeposited and solidifies on exchanger plates defining such channels.Coolerair is directed through another set of channels in the exchanger,and this outside air receives heat from the grease laden air, which maybe utilized for the heating of the building which houses the cookingfacility.

One object of the present invention is the provision of a heat exchangerutilized in the removal of grease and other contaminants from a movingmass of air. A further object is to provide within such exchanger awashing fluid dispenser means for washing the exchanger to cleanse it ofthe. grease and other contaminants that collect on exchanger surfaces inthe exchanger.

Other objects and advantages of the invention include improvements in acooking facility including in combination with a hood an exchangereffective to remove efficiently and thoroughly grease and likecomponents found in grease laden air, improvements in a cooking facilitywherein the heat possessed by grease laden air which is normallydischarged to the atmosphere is conserved by transferring such heat tomake up air, and improvements in a heat exchanger characterized by meansin the exchanger periodically for washing exchanger surfaces therein.

These and other objects and advantages are attained by'the inventionwhich will become more fully apparent as the following description isread in conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates, in. diagrammatic and somewhat simplified form, aheat exchanger installation for a building enclosure, where the heatexchanger forms part of a cooking facility, according to one embodimentof the invention; and

FIG. 2 is a perspective view illustrating in simplified form theinterior of a heat exchanger and means for washing channels therein.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings, andfirst of all more particularly to FIG. 1, illustrated at are portions ofa cooking facility, such as might be provided in a restaurant or otherdispenser of a large volume of prepared food. The cooking facilityincludes cooking means 12 for cooking the food prepared, which mighttake the form of burners, a hot plate, a fryer etc. Cooking means 12 islocated in the kitchen of the restaurant, which kitchen is housed withina building enclosure, diagramtically indicated in FIG. 1 by the dot-dashline 14, representing portions of the roof line of the buildingenclosure. I

Disposed over cooking means 12 in position to receive air laden withgrease and other contaminants normally produced as a result of thecooking process is hood means or assembly l6.-

As contemplated by this invention, the grease laden air which passes upinto hoodmeans 16 thence is channeled through a heat exchanger shown at18. The heat exchanger performs a number of functions, including theextraction of grease from the laden air prior to such air beingexhausted to the atmosphere outside the building enclosure, and thetransfer of the heat from the grease laden air to air flowing into thebuilding enclosure from the outside, which inflowing air may be make-upair replacing that removed through the hood.

Further explaining, heat exchanger 18 comprises a substantiallyrectangular elongated housing 20. Within the housing are a series ofheat exchanger plates, disposed substantially parallel to each other andextending along the length of the housing. The plates are laterallyspaced from each other, and define multiple channels extending along thelength of the housing. Alternate ones of these channels are utilized forthe transfer of greaseladen air through the exchanger. The channelsinterspersed with these alternate ones are utilized in the passage. ofinflowing relatively cool air, which may be used as make-up air.

With reference to FIG. 2, here there is illustrated in simplified forman assembly of exchanger plates such as might be provided within theexchanger housing discussed. The assembly in simplified form includesfive exchanger plates, illustrated at 22, 24, 26, 28 and 30. Each of theplates has a length substantially corresponding to the length of theexchanger housing in which the assembly is incorporated. The plates areshown provided with corugations extending transversely of their length,whereby air passing through the heat exchanger is given a degree ofturbulence and changes its direction of flow.

Each of the plates at each of its ends is split with a cut extendinglongitudinally of the plate. The cut parallels the longitudinal edges ofthe plate, and normally is made about midway between the longitudinaledges, thus to divide the end of each plate into a pair of tonguesegments, exemplified by segments 22a, 22b in plate 22, of substantiallyequal width and length.

49951. Se ment e fiashusa hsss pla e re shown bent in reversedirections. Thus, tongue segment 22a is bent to curve outwardly, whereit may meet with the housing of the exchanger which surrounds theassembly, and tongue segment 22b below segment 22a is bent to curveinwardly. Considering exchanger plate 24, its upper tongue segment 24ais bent inwardly, whereas its lower tongue segment 24b is bent outwardlyto meet with tongue segment 22b.

Where adjacent ends of tongue segments meet, they may be fixed together,using an overlying angle piece such as angle pieces 24 secured in placeas by crimping.

It will be noted that whereas upper tongue segment 22a of plate 22 isbent outwardly and the lower one 22b is bent inwardly, at the oppositeend of the exchanger plate assembly upper tongue segment 22c is bentinwardly whereas the lower one 22d is bent outwardly. This samerelationship holds true for the tongue segments at each set of ends ofan exchanger plate.

A divider member shown at 32 including a horizontal wall expanse 34 anda vertical marginal flange 36may be inserted into cuts forming thetongue segments, at

each set of ends of the exchanger plates in the assembly. The dividermember when positioned as shown in FIG. 2, serves to separate endportions of channels defined on opposite sides of the variousplatesnThus, and considering channel 42, the divider separates thischannel, where such is defined between tongue segments 28a and 26a, fromportions of channels 40 and 44 below the divider, defined between tonguesegments 30b, 28b and 26b, 24b, respectively.

As shown in FIG. 2, channels 38, 42, and 456, at the end of the plateassembly pictured at the bottom of the figure, open to the end of theassembly above the divider. At the opposite end of the assembly, thesechannels open up to the end of the assembly below the divider. Thereverse is true for channels 40, 44 and 48, which at the assemblypictured at the bottom of the figure open to the end of the assemblybelow the divider, and at the opposite end of the assembly open to theend of the assembly above the divider.

With the construction described, and assuming the presence of anencompassing housing 20, it should be obvious that one set of channelsmay be utilized for the passage of one body of gas through theexchanger, and an alternating set of channels may be utilized for thepassage of another volume of gas through the exchanger, with such bodiesof gas passing through multiple flow paths interspersed with each other.

Referring again to FIG. 1, hood means 16 includes a frusto conicallyshaped flange 16a at the top thereof forming an opening at the top ofthe hood. Secured to the hood and communicating with this opening is aconduit or duct 50. The opposite end of the duct joins with the lowerpart of exchanger housing 20 at the right end of the exchanger inFIG. 1. This places the interior of duct 50 in communication with theset of channels within the heat exchanger which open up to the bottom ofthe housing below divider member 32 at the right end of the exchanger.

It will be remembered from the description of the exchanger plateassembly set forth above, that the channels that open up to the bottomof the assembly at one end of the assembly open up to the top of theassembly at the opposite end of the assembly. Thus, the channels withinthe heat exchanger which communicate with duct 50, at the opposite endof the exchanger communicate with a duct 52 connecting with the upperend of the exchanger. Duct 52 is provided with a suitable motor-drivenfan in a blower assembly 54, and an exhaust or outlet 56 located abovethe roof of building enclosure 14. Running of the blower assembly isoperable to produce a flow of air through the exchanger in the directionof exhaust 56 indicated by the arrow 20A in FIG. 1.

Air which is withdrawn from the kitchen area customarily is at arelatively high temperature, having been warmed by the instrumentalitiesprovided in the kitchen for the cooking of food. As contemplated by thisinvention, the heat of this expelled air is utilized to raise thetemperature of a counterflowing mass of air, this air being usable, forinstance, as make-up air for the building enclosure where the kitchen islocated.

Referring to FIG. 1, a conventional filter assembly is designated at 60.The assembly includes the usual filtering material which functions tofilter air moving into the assembly from the left of the filter assemblyas pietured in FIG. I. The outlet from the filter assembly communicateswith the lower part of the heat exchanger at the left end of theexchanger in FIG. 1. Air

drawn through the filter, therefore, passes into the heat exchanger intothe set of channels which open to the bottom of the exchanger at theleft end in FIG. 1.

These same channels, which are interspersed with the channels carryingthe grease laden'air, open up to the top of the exchanger at the rightend of the exchanger in FIG. 1. Shown at 62 is a blowerassembly'including a fan having an inlet opening connecting with thesechannels at the top right hand end of the exchanger. Connecting with theexhaust from the blower assembly is a duct 64 joining with a valveassembly 66 leading to a pair of ducts 68, 70. Duct 70, for instance,may lead 0 h asteti r qith u ldin w sasdust .68 m y lead to thebuildings interior 't o provide a source of make-up air in the building.Valve assembly 66 is provided to control the proportion of air flowingthrough duct 64 which enters duct 70. This control is important, forinstance, in enabling a greater flow of air through this return duct 68under wintertime conditions, when maximum heating is desired, with alesser flow under more moderate conditions, when the need for heated airis diminished. With running of blower assembly 62, the flow offilteredatmospheric air through the exchanger is in the direction indicated byarrow 20B in FIG. 1.

Referring again to FIG. 1, extending along each of the channels carryingthe grease laden air in the exchanger, is an elongated circuit or tube72. A manifold 78 connects together one set of ends of these tubes. Theopposite ends of these tubes are closed off.

The tubes and manifold have been shown in FIG. 2, to illustrate withgreater clarity how the tubes may be incorporated in the heat exchangerwith such extending along the various channels defined between theexchanger plates; It will be noted that distributed along the top ofeach tube is a series of outlets 80.

As illustrated schematically in FIG. 1, the manifold is connected bypipe 79 to a source of hot water or other wash fluid 82, such as steam.Valve 86 controls the admission of such hot water to the manifold andtubes. A detergent supply, for introducing detergent to the waterflowing to the tubes, is shown at 84. Valves 85, 87, and venturi device88 are provided for controlling the amount of detergent withdrawn fromsupply 84 and introduced to the wash water flowing in conduit 79.

The tubes and manifold, and related. structure, constitute a wash fluiddispensing system or means provided to enable periodic cleaning of theexchanger, more particularly those surfaces defining the channels whichcarry grease laden air from the hood assembly. The outlets in the tubes,which are distributed along the tops of the tubes, eject hot water intothese channels, with such impinging upon the upper wall of the housingand cascading down the heat exchanger surfaces defining the sides of thechannels. Cleaning of the heat exchanger reduces fire hazard, andpromotes the efficiency of the heat exchanger.

As can be seen in FIG. 1, the heat exchanger is mounted in theinstallation with the base of the exchanger housing (which forms thefloor defining the bottom of the channels described) sloping from leftto right in the figure. This floor functions as a drain surface forthose channels which are subjected to washing periodically. A drain isshown at '90 which receives water collecting at the bottom of the heatexchanger housing and flowing along this drain surface. The housing mayhave adjacent its opposite ends, and extending up from the floor of thehousing, flanges such as depicted at 92, inhibiting the flow of waterout from the ends of the housing.

Duct 50 leading from the hood assembly and connecting with the heatexchanger may also be provided with a wash system. Thus, illustrated inFIG. 1 is a rotatable sprinkling-type dispenser 96 operable to directwash water about the interior of the duct. Conduit 97 supplying washwater to dispenser 96 may be connected in a suitable manner to pipe orconduit 79 supplying wash water to the tubes in the exchanger. indraining from the duct, the water flows down inner surfaces of the ductto collect on the outer side of frusto conical flange 16a. At the baseof the space defined between this fiange and duct 50 is a drain 98connected by conduit 99 to drain tube 90, providing for the flow of washwater outside the system.

' During operation of the kitchen facility described, the grease andcontaminant laden air coming from the grill, burner, fire or othercooking means, travels upwardly into the hood assembly and through a setof channels in the heat exchanger, as the result of the suction producedby operation of fan assembly 54, with such air ultimately being ejectedinto the atmosphere outside the enclosure. On traveling through the heatexchanger, the grease and contaminants contained in the air collect onthe surfaces of the exchanger plates defining the channels through whichthe grease laden air travels. The exchanger plates, by reason of theirrelatively cool state, promote condensation and solidification of thegrease and thus separation of the grease from the moving mass of air.

The heat from the air which is withdrawn through the hood is transferredto the inflowing air passing through the exchanger. As a result, themake-up air is warmed without the use of energy from another energysource. The incoming air is filtered, and obtained from the atmosphereat a point remote from exhaust 56. Thus, it is odor free and clean.

Periodic cleaning of the heat exchanger and duct 50 is easily performedutilizing the water dispensing system described. With cleaning, theefficiency of the heat exchanger is returned to its maximum, andcollections of grease, etc. which constitute a fire hazard are removed.

It should be obvious that the apparatus disclosed has a number ofadvantages. It is appreciated that various changes and variations may bemade in the construction. It is desired to cover all such changes andvariations as are embraced within the invention as set forth herein.

It is claimed and desired to secure by Letters Patent:

1. A heat exchanger system for a kitchen cooking facility including acooking area, comprising:

a hood assembly adapted for use in the cooking area to receive air ladenwith grease and other products of cooking from such cooking area,

duct work connecting with the hood assembly for carrying such laden airto a region outside the cooking facility,

a heat exchanger positioned outside of said hood assembly and havingfirst passage means defined therein, said first passage meanscommunicating with said hood assembly through said duct work wherebysaid first passage means and duct work de' fine a course for the ladenair leading to said region,

said heat exchanger having second passage means provided within the heatexchanger and in heat exchanging relation with said first passage means,

additional duct work adapted to connect a source of relatively cool airoutside of said kitchen to said second passage means whereby a coursefor cooling airis defined from said source through the heat exchanger,and

washing fluid dispensing means provided within the heat exchanger forwashing said first passage means.

2. The combination of claim 1, wherein said heat exchanger comprisesmultiple exchanger plates having a first set of heat exchange surfaces,said first passage means comprises multiple laterally spaced channelsdefined by said first set of heat exchange surfaces, and the heatexchanger is provided with a wash fluid dispensing system comprising aplurality of conduits extending longitudinally along said channels withoutlets distributed along the length of said conduits.

3. The combination of claim 1, wherein said cooking facility is housedwithin a building enclosure, and said first-mentioned duct work leadsfrom said building enclosure to a region outside the enclosure, and saidsource of relatively cool air comprises atmospheric air outside saidenclosure, and said additional duct work has an exhaust within saidbuilding enclosure.

4. The combination of claim 3, wherein said additional duct work hasanother exhaust outside said building enclosure, and which furthercomprises adjustable means controlling the amount of air exhaustedthrough said first-mentioned and said other exhaust.

5. A heat exchanger system for a building enclosure housing a kitchinarea having a food cooking means, comprising:

a hood assembly positioned to receive air passing over said cookingmeans and laden with grease and other contaminants produced by thecooking of food,

a heat exchanger having first and second passage means extending withinsaid exchanger and in heatexchanging relation, said heat. exchangerbeing positioned outside of said hood assembly,

a first duct connecting said hood assembly and one end of said firstpassage means in said exchanger,

an outlet means connecting with the other end of said first passagemeans, for connecting said first passage means with the atmosphereoutside of said building enclosure,

an inlet means for connecting a source of, cool air outside saidenclosure to one end of said second passage means,

a second duct connecting with the other end of said second passage meansincluding an exhaust outlet adapted to exhaust the air within saidbuilding enclosure,

means for moving air to said first and second ducts,

and

washing fluid dispensing means provided within the heat exchanger forwashing said first passage means of said exchanger.

. mm M GIBSDN JR.

UNITED STATES PATENT OFFICE CERTH ICATE OF @URRECTION Patent: No 3 r 827r 34 3 Dated August 6 1974 hwemmw) WILLIAM J. DARM It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1 line 1.6,v after 'Cooler" insert --=-outside--;

Column 2, line 34, "oorugations" should be ---corruga.tion8-;

Column 3, line 62, "where" should be --where-;

Column 4, line 28, "circuit" should be --conduit-.

Signed m sealed this 22nd day of October 1974.

Attesm o. MARSHALL DANN Attestimg Officer Commissioner of Patents

1. A heat exchanger system for a kitchen cooking facility including acooking area, comprising: a hood assembly adapted for use in the cookingarea to receive air laden with grease and other products of cooking fromsuch cooking area, duct work connecting with the hood assembly forcarrying such laden air to a region outside the cooking facility, a heatexchanger positioned outside of said hood assembly and having firstpassage means defined therein, said first passage means communicatingwith said hood assembly through said duct work whereby said firstpassage means and duct work define a course for the laden air leading tosaid region, said heat exchanger having second passage means providedwithin the heat exchanger and in heat exchanging relation with saidfirst passage means, additional duct work adapted to connect a source ofrelatively cool air outside of said kitchen to said second passage meanswhereby a course for cooling air is defined from said source through theheat exchanger, and washing fluid dispensing means provided within theheat exchanger for washing said first passage means.
 2. The combinationof claim 1, wherein said heat exchanger comprises multiple exchangerplates having a first set of heat exchange surfaces, said first passagemeans comprises multiple laterally spaced channels defined by said firstset of heat exchange surfaces, and the heat exchanger is provided with awash fluid dispensing system comprising a plurality of conduitsextending longitudinally along said channels with outlets distributedalong the length of said conduits.
 3. The combination of claim 1,wherein said cooking facility is housed within a building enclosure, andsaid first-mentioned duct work leads from said building enclosure to aregion outside the enclosure, and said source of relatively cool aircomprises atmospheric air outside said enclosure, and said additionalduct work has an exhaust within said building enclosure.
 4. Thecombination of claim 3, wherein said additional duct work has anotherexhaust outside said building enclosure, and which further comprisesadjustable means controlling the amount of air exhausted through saidfirst-mentioned and said other exhaust.
 5. A heat exchanger system for abuilding enclosure housing a kitchin area having a food cooking means,comprising: a hood assembly positioned to receive air passing over saidcooking means and laden with grease and other contaminants produced bythe cooking of foOd, a heat exchanger having first and second passagemeans extending within said exchanger and in heat-exchanging relation,said heat exchanger being positioned outside of said hood assembly, afirst duct connecting said hood assembly and one end of said firstpassage means in said exchanger, an outlet means connecting with theother end of said first passage means, for connecting said first passagemeans with the atmosphere outside of said building enclosure, an inletmeans for connecting a source of cool air outside said enclosure to oneend of said second passage means, a second duct connecting with theother end of said second passage means including an exhaust outletadapted to exhaust the air within said building enclosure, means formoving air to said first and second ducts, and washing fluid dispensingmeans provided within the heat exchanger for washing said first passagemeans of said exchanger.